Cable armor cutter



June l23, 1953 z. -o. sT. PALLEY CABLE ARMOR CUTTER Filed June 25, 1952 IN V EN TOR.

Patented June v23,` 1953 CABLE ARMOR CU'HER Zoltan 0. St. Palley, Branford, Conn. Application June 25, 19542, ASerial o. 295,525

Y (o1. ,2c- 67) Claims.

This invention, which is a continuation in part In the instalation of these cames the cuse tomary way is to cut the armor diagonally by means of a hack-saw. Due to the curvature of the surface of the cable, in such a diagonal cut the penetration of a straight hack-saw is the deepest in the center of the cut, decreasing gradually to zero toward the ends of the cut. Hence, if we limit the maximum penetration to the inside surface of the armor, the cut in the armor stripV will be incomplete. if we attempt to out the armor strip completely by a straight hack-saw, the maximum penetration of the saw in the center of the cut will be so deep that the insulation of the wires may be damaged, causing a dangerous hazard in the electrical installation.

Theobject of my invention is to preclude the damaging of the insulation when cutting the BX armor, by providing a cutting means which can cut the armor strip in a line practically parallel to the axis of the cable, and thereby, can sever the armor strip completely Without vpenetrating Conversely,

at any point deep enough to come in contact with the insulation.

Another object of my invention is to provide a rotary cutting means which is easily replaceable and is inexpensive, hence, a very high cutting eiciency can be maintained with very little effort and at a low cost.

Another object of my invention is to provide a tool for the cutting of the BX armor, in which the cutting means is withdrawn during the clamping of the cable in order to protect the cutting means from impact and from being applied with the wrong direction of rotation.

Another object of my invention is to provide a cutting tool for BX armor, in which the same crank serves for the tightening of the clamping means and also forthe rotating of the cutting means, resulting in great ease and convenience in the handling of the tool.

A further object of my invention is to provide a tool which cuts the BX armor always the right way, entirely independently of the skill and attention of the operator and without deforming the BX armor, and without the possi-' bilityv of causing bodily injury to the operator, which is a too frequent occurrence when cutting BX armor by a hack-saw. e

Other objects Aand advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing, forming a part of this application, wherein, for the purpose of illustration, is shown a preferred embodiment of my invention,

Figure 1 is a plan view of my cable armor cutter,V

Figurev 2 is a vertical longitudinal section through the same, with the crank inthe cutting position,

Figure 3 is a front view of the cutting means,

Figure 4 is a vertical longitudinalv section of my cable armor cutter, with the crank in the clamping position,

Figure 5 is a side View of the cable, showing the completed cut.

Referring to the drawing, wherein like reference numerals are employed to designate like parts, the numeral 2 designatesv a cup-shaped clamp, having a cavity for receiving an armored cable I. Rib-shaped portion 3 of said cavity projects into the spiral groove ofthe armored cable I, for positioning the cable axially.

Tubular clamping screw 4 is in threaded relation with clamp 2, so that by turning the Aclamping screw 4 cable I can be held securely in clamp 2. dClamping screw 4 has notches 5 at its free en Rotatably and slidably mounted within the clamping screw 4 is plunger 6, which at'one end carriesthe cutting means 1, consisting of a holesaw or hollow-drill, secured by means of split washer 9 and retaining screw I0.

Plunger 6 is surrounded by spring 8, interposed between the shoulder of the plunger and the inverted flange of the clamping screw 4, so

- as to pressV the cutting means 1 against the cable I.

Pivotally connected `to plunger 6 is a crankI I, having a handle I2 anda lugv I3.y Said pivotal connection permits the crank II to be swung up from the cutting position, shown in Fig. 2 of vthe drawing, into the clamping position, shown -in Fig. 4. In the cutting position crank I'I is used for rotating plunger 6 together with the vcutting means 'I, heretofore called hole-saw or hollow-drill. In the cutting position crank II may be used also to exert manually in axial pressure on the plunger to supplementthe pressure of the spring 8. 'In the clamping position crank II engages the clamping screw 4 by means oflug I3 projecting into notch 5, so that crank I I. Y

the clamping screw can be rotated by means of the clamping.

Fig. 3 of the drawing shows a front View of the cutting means 1 which, in this preferred form,

consists of a short saw blade bent in a circle and with the ends of the blade not attached. It will be within the spirit and scope of this invention to use closed annular, cylindrical; conical, cup-shaped or any other type'fof hole'- saws or hollow-drills, made of vany suitable mai by turning said crank; means for withdrawing terial, provided they can penetrate the armor of the cable when subjected to rotation andA simultaneous axial pressure.

5 of the drawing shows a side YView ofthe thecut which is the nearest to the center line of the cable. It is an essential feature of my inventionY that the cutting means 1 is located tangentially to a plane passing through the eenter line of the `cable I, giving a cut which severs the armor strip completely, without pene,- trating at any point deep enough to come in contact with the insulation within the armor.

-shown in Fig. 2 lof the drawing, cutting means 1 is recessed in the plunger 6, so that the maximum penetration is limited by the projection Aof the cutting means 1 beyond the -end of the plunger 6. In my invention this projection oi cutting means 1 Vis just sufficient to reach the.

innermost point I5 of the armor strip, but will not rreach the Ainsulation within the armor of 'the cablef .he method of operation will be as follows: @rank II is Ymovedinto the clamping position, cable AI is inserted into the cavity -of clamp 2 and clamping screw vl is turned by means of crank 4vI Iuntil the cable 'is firmly clamped.

Ehen. the crankI-l is swung into the cutting positionand is rotated by means of handle I2. After a few turns the cut in the armor is com.- pletedrjwhich is noticed bythe ease ofjturning 01.1.6 Crnk- .Y Vlhen, the crank II is swung back intoI the clamping position and the cable is unclamped. In this positionthe tool is ready toV receive the next cable for cutting.

`VVIt is to be understood that the form of my in- .vention,herewith shown and described, is to be taken as La preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to.. without departing from the lspirit of my invention, or lthe scope V'of Ythe subjoined claims. I. claim:

l. A clamp adapted to hold and axially position a .BX cable; a hollow clamping screw, directed toward the side of said Vcable and having threaded relation with said clamp; a plunger rotatably .and slidably .mounted within vsaid clamping screw; a hole-saw secured to one end of said plunger; a spring to press said hole-saw against z'said cable; a crank for the manual rotation of said plunger, having a pivotal connec1 tion with said plunger, said crank being adapted to Withdraw -said `'hole-saw from contactwith said cable and to engage said clamping screw for the purpose of rotation, when said crank is swung about said pivotal connection.

2. A clamp adapted to hold and axially position an armored cable; a hollow clamping screw, directed toward the side of said cable and having threaded relation with said clamp; a spring pressed plunger rotatably and slidably mounted within said clamping screw; a hole-saw secured rto one end of said plunger;` a crank having two positions: cutting and lclamping positions; connecting means adapted to rotate said plunger said hole-saw from contact with said cable when said crank is moved into the clamping position; means (for Vobtaining driving engagement between said crank and clamping screw when said crank is in the clamping position.

3. A .clamp adapted to hold and axially position a BX cable; a tubular clamping screw in threaded relation with -saidl clamp.; a .spring pressed hollow-drill rotatably and axially slidably mounted within said clamping screw.; a crank, adapted to selectively rotate either both of said clamping screw and said hollow-drill, `or only said hollow-drill; meansv for withdrawing said hollow-drill from contact with said .cable before rotating said clamping screw.

4. A clamp adapted to hold and axially -position a BX cable; -a tubular clamping screw in threaded relation with said clamp; a spring pressed hollow-drill rotatably and -slidably mounted within said clamping screw; a crank having two positions: cutting and clamping positions; connecting'means adapted `to rotate said hollow-drill by turning said crank, when said crank is in the cutting position; connecting means adapted torotate said clamping screw by turning said crank, when said crank is in the clamping position. Y

5. Clamping means adapted to hold and axially position an armored cable; spring pressed -hollow-drill, directed tothe side-of Vsaid armored cable and being rotatably and axially slidably mounted in said clamping :means 'a crank, hav-.- ing two positions and being adapted torotate said hollow-dr-ill'when said crankis in the first position and to withdraw said hollow-drill from contact with the cable when said crank ismoved into the second position.

6. In a tool for cutting the armor strip of a BX cable; a clamp adapted 'to .hold 'a BX cable; a positioning rib secured to saidrcla'mp and projecting into the spiral groove of said cable, for the axial positioning Aof said. cable; a `tubular clamping screw in threaded .relation with said clamp; ya spring V.pressed plunger .rotatably and slidably mounted within said clamping screw.; ya hole-sawV secured to Yone Yend of said plunger, -said hole-saw being tangential to a plane .passing through 'the center Vline Yof said cable and said hole-saw being recessed into. the end of said plunger so as to limit the maxi-mum penetration of the hole-saw Vto the Vthiclnfxessof the armor strip. Y

'1. In a tool for-cutting the-armorstrip of `a BXcable; clamping vmeans having a cavity with rib projecting into the -spir-al groove -of said cable,V for axially position-ing and securely holding said cable; a rotatable and axially slidable hollowdrill mounted tangentially Vto a plane passing through the axis of said cable aspri-ng for pressing said hollow-drillgagainst ls 'aicl cable; :a crank for the marinai rotation Orl-said hollow drill, said crank being adapted to1transrriitanax"V Vagriual pressure to said hondo-drm iin order-'toisupplement the spring pressure for the purpose of controlling the speed of the cutting.

8. In a tool for cutting the armor strip of a BX cable; clamping means for holding said cable; a plunger directed toward the side of said cable and rotatably and axially slidably mounted in said clamping means; a hole-saw recessed into one end of said plunger so as to prevent its penetration beyond the innermost point of said armor strip; positioning means, integral with said clamping means, to position axially said armor strip with respect to said hole-saw; a spring for pressing said hole-saw against said cable; means for the manual rotation of said hole-saw.

9. In a tool for cutting the armor strip of a BX cable; a clamp adapted to hold said cable; a tubular clamping screw, in threaded relation with said clamp, directed toward the side of said cable; a hollow-drill, rotatably and slidably mounted within said clamping screw with an axial clearance, which permits the turning of said screw until said cable is securely clamped, without pressing said hollow-drill against said cable; manual means` adapted to rotate said hollow-drill and also to transmit simultaneously an axial pressure on said hollow-drill, by the use of one hand, in order to control the speed of the cutting;

6 mechanical stop to limit the penetration of said hollow-drill.

10. In a manually operated portable tool for cutting the armor strip of a BX cable; a clamp, having a cavity adapted to receive said cable; a tubular clamping screw, in threaded relation with said clamp, and adapted to secure said cable in said cavity; a hollow-drill, rotatably and slidably mounted Within said clamping screw, and being so deeply recessed that it will not touch the cable when said cable is clamped by means of said screw; a crank, adapted to rotate and also axially press said hollow-drill, so as to effect and control the cutting by the use of one hand, in order to have the other hand free for the holding of said portable tool; a mechanical stop to limit the axial sliding of said hollow-drill.

ZOLTAN O. ST. PAlLEY.

Y References Cited in the ille of this patent UNITED STATES PATENTSA Number Name Date 1,677,922 Kastzler July 24, 1928 2,031,470 Eck et al Feb. 18, 1936 2,573,991 Schildknecht Nov. 6, 1951 

